Polymer Grafting to Polydopamine Free Radicals for Universal Surface Functionalization

Abstract

Modifying surfaces using free radical polymerization (FRP) offers a means to incorporate the diverse physicochemical properties of vinyl polymers onto new materials. Here, we harness the universal surface attachment of polydopamine (PDA) to “prime” a range of different surfaces for free radical polymer attachment, including glass, cotton, paper, sponge, and stainless steel. We show that the intrinsic free radical species present in PDA can serve as an anchor point for subsequent attachment of propagating vinyl polymer macroradicals through radical–radical coupling. Leveraging a straightforward, twofold soak-wash protocol, FRP over the PDA-functionalized surfaces results in covalent polymer attachment on both porous and nonporous substrates, imparting new properties to the functionalized materials, including enhanced hydrophobicity, fluorescence, or temperature responsiveness. Our strategy is then extended to covalently incorporate PDA nanoparticles into organo-/hydrogels via radical cross-linking, yielding tunable PDA–polymer composite networks. The propensity of PDA free radicals to quench FRP is studied using in situ 1H nuclear magnetic resonance and electron paramagnetic resonance spectroscopy, revealing a surface area-dependent macroradical scavenging mechanism that underpins PDA–polymer conjugation. By combining the arbitrary surface attachment of PDA with the broad physicochemical properties of vinyl polymers, our strategy provides a straightforward route for imparting unlimited new functionality to practically any surface.

MOF‐derived bimetallic NiCo nanoalloys for the hydrogenation of biomass‐derived levulinic acid to γ‐valerolactone

“…Combined with the above Ni 2p and Co 2p XPS results, the metal oxide should be mainly attributed to CoO species owing to the oxophilic property of Co. X‐band electron paramagnetic resonance (EPR) spectroscopy was also performed for Ni 1 Co 1 /C (Figure 2D). A single‐line asymmetric resonance signal at g = 2.001 was clearly observed, which can be assigned to the carbon‐centered radical in the sp 2 carbon‐related dangling bonds of the free‐carbon phase 40–42 . This carbon‐centered radical might be associated with cationic defects within the carbon backbone, which can accept electrons to improve the electronic interaction with reactants and thus improve the catalytic performance of Ni 1 Co 1 /C 43 …”

“…A single-line asymmetric resonance signal at g = 2.001 was clearly observed, which can be assigned to the carbon-centered radical in the sp 2 carbon-related dangling bonds of the free-carbon phase. [40][41][42] This carbon-centered radical might be associated with cationic defects within the carbon backbone, which can accept electrons to improve the electronic interaction with reactants and thus improve the catalytic per- S1 and S2). S4).…”

Perspectives and Current Trends on Hybrid Nanocomposite Materials for Photocatalytic Applications

“…Furthermore, Nothling et al showed how PDA works as an anchor point for the attachment of propagating vinyl polymer macroradicals through radical-radical coupling. [98] The process further [95] Copyright 2022, Elsevier. b) (Left) Optical images of a PDA membrane subjected to light-induced contraction at ambient conditions.…”

“…Furthermore, Nothling et al showed how PDA works as an anchor point for the attachment of propagating vinyl polymer macroradicals through radical–radical coupling. [ 98 ] The process further enhances the rich chemistry of PDA and expands its potential for the functionalization of multiple surfaces.…”

PSS-dispersed dopamine triggered formation of PAA adhesive hydrogel as flexible wearable sensors

“…15 It is also identied as a small-molecule mimic of mussel foot proteins, which can undergo autooxidation and then selfpolymerize under alkaline conditions to generate polydopamine (PDA) materials. [15][16][17][18][19][20][21][22] DA derivatives and PDAincorporated hydrogels exhibit strong adhesiveness toward various organic and inorganic substrate surfaces, and human skin. [8][9][10][11][12] Radical polymerization using additional initiators is a typical method to prepare mussel-inspired hydrogels.…”